German Patent Application No. DE 40 03 227, for instance, describes a fuel injector which includes a core surrounded by a solenoid coil, an armature by which a valve-closure member cooperating with a fixed valve seat is actuable with the aid of a connecting tube welded to the armature; a tubular metal intermediate part which, by welding, is sealingly connected to an end of the core facing the armature via its one end, and to a tubular connecting part via its other end; and at least one bracket-type conducting element, which overlaps the solenoid coil and, by welding, is connected to the connecting part by its end facing the valve-closure member, and to the core via its other end. In each case the welding of two overlapping components of the fuel injector is implemented in a region of reduced cross-section of one of the two components to be welded together.
A particular disadvantage of this fuel injector is that the production of the connections between the individual components of the fuel injector is complicated and therefore time-consuming and cost-intensive. Furthermore, the welded points are thermally stressed and thus lose strength and flexural stiffness, which can result in considerable resonances due to housing parts having varying thickness and in an associated generation of noise when operating the fuel injector. In addition, a support ring, which is injection-molded underneath the seal on the side of the intake manifold, has the effect that contact points between the housing and valve sleeve are not reliably sealed, which may lead to problems due to poor sealing, especially during turbo-operation of the internal combustion engine.